Question

It is estimated that there are 10^20 grains of sand on a beach in Florida in April. The beach is heavily eroded by tourists over the peak summer holiday season. Approximately one hundredth of the beach is removed as a result of this erosion. How many grains of sand are removed from the beach?

Answer 1

c

Explanation:

Answer 2

`\bf \textit{how much is }(1)/(100)\quad of \quad 10^(20)?\implies \stackrel{\textit{one hundredth}}{\cfrac{1}{100}}\cdot 10^(20)\implies \cfrac{1}{10^2}\cdot 10^(20) \\\\\\ 10^(-2)\cdot 10^(20)\implies 10^(-2+20)\implies 10^(18) \\\\\\ 1,000,000,000,000,000,000~grains`